Liquid crystal display

Abstract

In a liquid crystal display ( 1 ), a transparent electrode ( 100 ) constituting a display liquid crystal cell ( 30 ) has a plurality of patterns ( 102, and the like) for forming a desired pattern in the outer circumferential part ( 101 ) forming the whole display region, and transparent electrodes ( 13 a, 13 b ) are sandwiching at least a part of liquid crystal molecules of a liquid crystal layer ( 20 ). When voltage application control of the plurality of patterns ( 102, and the like) is performed, respectively, for the whole display region displayed by bright display or dark display, a desired pattern can be displayed by reversed bright/dark display of the bright/dark display of the whole display region. Furthermore, the bright/dark display of at least a part of the whole display and the desired pattern can be reversed by applying a voltage to the transparent electrodes ( 13 a, 13 b ) and changing the orientation of whole liquid crystal molecules of the liquid crystal layer ( 20 ) to the direction parallel with the normal to a substrate ( 11 ).

The invention claimed is: 
     
       1. A liquid crystal display comprising:
 an upside liquid crystal cell composed of upside substrates disposed parallel to each other, a pair of plate-shaped transparent upside electrodes disposed parallel to the upside substrates between the upside substrates, and an upside liquid crystal layer sealed in a layered form between the pair of upside electrodes; 
 a downside liquid crystal cell composed of downside substrates disposed parallel to each other, a pair of plate-shaped transparent downside electrodes disposed parallel to the downside substrates between the downside substrates, and a downside liquid crystal layer sealed in a layered form between the pair of downside electrodes, and disposed on the lower surface of the upside liquid crystal cell to join therewith; 
 an upside polarizer allowing linearly polarized light of a predetermined transmission axis direction to be transmitted therethrough, and disposed on the upper surface of the upside liquid crystal cell to join therewith; and 
 a downside polarizer allowing linearly polarized light of a predetermined transmission axis direction to be transmitted therethrough, and disposed on the lower surface of the downside liquid crystal cell to loin therewith; 
 wherein upside liquid crystal molecules constituting the upside liquid crystal layer are positioned to twist in a first twist direction along a helical axis parallel to the normal of the upside substrates, while downside liquid crystal molecules constituting the downside liquid crystal layer are positioned to twist in a second twist direction along a helical axis parallel to the normal of the downside substrates, and the first twist direction is opposite to the second twist direction; 
 wherein the pre-tilt angle of the upside liquid crystal molecules positioned in the upper-end vicinity of the upside liquid crystal layer is in opposite direction to and has almost the same degree as that of the downside liquid crystal molecules positioned in the lower-end vicinity of the downside liquid crystal layer; and the pre-tilt angle of the upside liquid crystal molecules positioned in the lower-end vicinity of the upside liquid crystal layer is in opposite direction to and has almost the same degree as that of the downside liquid crystal molecules positioned in the upper-end vicinity of the downside liquid crystal layer; 
 wherein the director of the upside liquid crystal molecules positioned in the lower-end vicinity of the upside liquid crystal layer is 180-degree opposite to that of the downside liquid crystal molecules positioned in the upper-end vicinity of the downside liquid crystal layer; 
 wherein one electrode pair of the pair of upside electrodes and the pair of downside electrodes has a plurality of pattern electrodes forming a desired pattern among the total electrodes forming an entire display area; 
 wherein the other electrode pair of the pair of upside electrodes and the pair of downside electrodes sandwiches at least a portion of the upside liquid crystal molecules or at least a portion of the downside liquid crystal molecules; 
 wherein with respect to the entire display area displayed by bright display or dark display, each of the plurality of pattern electrodes is under voltage application control so as to display the desired pattern by bright and dark display opposite to the entire display area; and 
 wherein a voltage is applied to the other electrode pair so as to change the director of at least a portion of the upside liquid crystal molecules or the director of at least a portion of the downside liquid crystal molecules to a direction parallel to the normal of the upside substrates or to a direction parallel to the normal of the downside substrates, thereby reversing the bright and dark displays of at least a portion of the entire display area and at least a portion of the desired pattern; and 
 wherein the twisted angle of the upside liquid crystal molecules relative to the first twist direction and the twisted angle of the downside liquid crystal molecules relative to the second twist direction are equal to or above 90 degrees and below 180 degrees. 
 
     
     
       2. The liquid crystal display according to  claim 1 , wherein the pair of upside electrodes and the pair of downside electrodes are configured by utilizing transparent electrodes such as those of ITO and the like. 
     
     
       3. A liquid crystal display comprising:
 an upside liquid crystal cell composed of a pair of transparent upside substrates disposed parallel to each other, and an upside liquid crystal layer sealed in a layered form between the pair of upside substrates; 
 a downside liquid crystal cell composed of a pair of transparent downside substrates disposed parallel to each other, a pair of plate-shaped transparent upside electrodes disposed parallel to the upside substrates between the upside substrates, and a downside liquid crystal layer sealed in a layered form between the pair of downside substrates, and disposed on the lower surface of the upside liquid crystal cell to join therewith; 
 an upside polarizer allowing linearly polarized light of a predetermined transmission axis direction to be transmitted therethrough, and disposed on the upper surface of the upside liquid crystal cell to join therewith; and 
 a downside polarizer allowing linearly polarized light of a predetermined transmission axis direction to be transmitted therethrough, and disposed on the lower surface of the downside liquid crystal cell to join therewith, 
 wherein upside liquid crystal molecules constituting the upside liquid crystal layer are positioned to twist in a first twist direction along a helical axis parallel to the normal of the upside substrates, while downside liquid crystal molecules constituting the downside liquid crystal layer are positioned to twist in a second twist direction along a helical axis parallel to the normal of the downside substrates, and the first twist direction is opposite to the second twist direction; 
 wherein the pre-tilt angle of the upside liquid crystal molecules positioned in the upper-end vicinity of the upside liquid crystal layer is in opposite direction to and has almost the same degree as that of the downside liquid crystal molecules positioned in the lower-end vicinity of the downside liquid crystal layer, while the pre-tilt angle of the upside liquid crystal molecules positioned in the lower-end vicinity of the upside liquid crystal layer is in opposite direction to and has almost the same degree as that of the downside liquid crystal molecules positioned in the upper-end vicinity of the downside liquid crystal layer; 
 wherein the director of the upside liquid crystal molecules positioned in the lower-end vicinity of the upside liquid crystal layer is 180-degree opposite to that of the downside liquid crystal molecules positioned in the upper-end vicinity of the downside liquid crystal layer; and 
 wherein the twisted angle of the upside liquid crystal molecules relative to the first twist direction and the twisted angle of the downside liquid crystal molecules relative to the second twist direction are equal to or above 90 degrees and below 180 degrees. 
 
     
     
       4. The liquid crystal display according to  claim 3 , wherein the upside liquid crystal molecules and the downside liquid crystal molecules are derived from twisted nematic liquid crystal having an identical birefringent property. 
     
     
       5. The liquid crystal display according to  claim 3 , wherein at least one is almost parallel to the other between the predetermined transmission axis direction of the upside polarizer and the director of the upside liquid crystal molecules positioned in the upper-end vicinity of the upside liquid crystal layer, and between the predetermined transmission axis direction of the downside polarizer and the director of the downside liquid crystal molecules positioned in the lower-end vicinity of the downside liquid crystal layer.